generated: '2026-07-22'
method: derived
source: >-
  Derived from https://www.marketaux.com/documentation (authentication, errors,
  pagination, date/encoding conventions) and openapi/marketaux-openapi.yml;
  well-known probes of www.marketaux.com and api.marketaux.com (2026-07-22).
standards:
  - id: api-key-auth
    conforms: true
    evidence: Single query-parameter API token (api_token) documented for every endpoint.
  - id: oauth2
    conforms: false
    evidence: No OAuth 2.0 flows documented; no /.well-known/oauth-authorization-server (404).
  - id: oidc
    conforms: false
    evidence: No /.well-known/openid-configuration on www.marketaux.com or api.marketaux.com (404).
  - id: rfc9457-problem-details
    conforms: false
    evidence: >-
      Errors use a vendor envelope {"error": {"code", "message"}} with
      application/json, not application/problem+json.
  - id: pagination
    conforms: true
    evidence: >-
      Page-based pagination (page + limit parameters, meta.found/returned/
      limit/page response fields) documented on all list endpoints; 20,000
      max result window.
  - id: rate-limit-headers
    conforms: true
    evidence: >-
      X-RateLimit-Limit (60-second window, 429) and X-UsageLimit-Limit (daily
      quota, 402) headers documented in the error reference.
  - id: idempotency
    conforms: false
    evidence: No Idempotency-Key contract; the API surface is GET-only.
  - id: iso8601-dates
    conforms: true
    evidence: >-
      All dates are UTC (GMT); published_* parameters accept ISO 8601-style
      Y-m-d\TH:i:s formats and responses return ISO 8601 timestamps.
  - id: iso3166-country-codes
    conforms: true
    evidence: countries parameters use ISO 3166-1 two-letter country codes per the docs.
  - id: json-api
    conforms: false
    evidence: Plain JSON envelope (meta/data), not the JSON:API media type.
  - id: openapi-published
    conforms: false
    evidence: >-
      No machine-readable OpenAPI/Swagger published by the provider; the spec
      in openapi/ was generated from the HTML documentation.